Question

How does the stele differ in the monocot and dicot roots?

• A. In the arrangement of xylem and phloem
• B. In pith region
• C. In the number of xylem bundles
• D. Both b and c

Answer 1

Answer: (D)

Both b and c
The stele is the central region of the roots and stems. Pericycle, pith, and vascular tissues are the components of stele.
Pith is made up of parenchyma cells that store and transport nutrients in the plant body.
In the dicot root, the pith is small and inconspicuous whereas, in the monocot root, the pith is large and well developed.

Dicot root has two (diarch) to four (tetrarch) bundles of xylem and phloem.
Monocot root has more than six (polyarch) bundles of xylem and phloem.
The arrangement of xylem and phloem is the same in dicot and monocot roots.
Xylem and phloem are arranged in an alternate manner along different radii. This type of arrangement is called radial, a characteristic anatomical feature of roots. Hnce the monocot and dicot roots differ in the pith region and in the number of xylem and phloem bundles.


A B
Transverse section of monocot (A) and dicot roots (B)